TMS320F28P650DK: internal 1.2V LDO power dissipation, recommendation for external 1.2V switching power supply

Gunter Schmer

Part Number: TMS320F28P650DK
Other Parts Discussed in Thread: TPS74801-Q1, TPS7A88-Q1

Hi all,

looking at the max power consumption for the heavy load from the datasheet, for VREG enabled vs VREG disabled, it looks like there is approx 700mW dissipated in the internal LDO, which is a pretty high number.

Do we generally recommend to use an external supply for the 1.2V supply?

For efficiency reasons, is there a TI switching power supply part we can recommend for the 1.2V supply?

We see the voltage tolerance for the 1.2V rail in the datasheet. Is there a ripple requirement on this rail, so we can check on for an appropriate switching power supply?

Thanks!
--Gunter

over 2 years ago

0 Hareesh Janakiraman over 2 years ago

TI__Guru* 95315 points

Gunter Schmer said:
Do we generally recommend to use an external supply for the 1.2V supply?

If power consumption is very important, then an external source for 1.2v is desirable.

Gunter Schmer said:
For efficiency reasons, is there a TI switching power supply part we can recommend for the 1.2V supply?

Let me check with the LaunchPad team.

Gunter Schmer said:
Is there a ripple requirement on this rail, so we can check on for an appropriate switching power supply?

Even with the ripple, the voltages should not stray beyond the MIN & MAX values shown in the datasheet.

0 Susmitha Bumadi over 2 years ago

TI__Expert 3350 points

Hi Gunter,

If you intend to have a safety system, LDO recommended for 1.2 V is TPS7A88-Q1 which will meet the power requirements. For non-safety application, LDO recommended for 1.2 V is TPS74801-Q1.

Thanks,

Susmitha.

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TMS320F28P650DK: internal 1.2V LDO power dissipation, recommendation for external 1.2V switching power supply